This invention relates to N-[[6-methoxy-5-(trifluoromethyl)-1-naphthalenyl]thioxomethyl]-N-methylgly cine S-oxide and the amide thereof, to the processes for their preparation, to methods for using the derivatives, and to pharmaceutical preparations thereof. The derivatives have pharmaceutical properties which render them beneficial for the treatment of diabetes mellitus and associated conditions.
For many years diabetes mellitus has been treated with two established types of drugs, namely insulin and oral hypoglycemic agents. These drugs have benefited hundreds of thousands of diabetics by improving their well-being and prolonging their lives. However, the resulting longevity of diabetic patients has led to complications such as neuropathy, nephropathy, retinopathy, cataracts and atherosclerosis. These complications have been linked to the undesirable accumulation of sorbitol in diabetic tissue, which in turn resulted from the high levels of glucose characteristic of the diabetic patient.
In mammals, including humans, the key enzyme involved in the conversion of hexoses to polyols (e.g. the sorbitol pathway) is aldose reductase. J. H. Kinoshita and collaborators, see J. H. Kinoshita et al, Biochem. Biophys. Acta, 158, 472 (1968) and references cited therein, have demonstrated that aldose reductase plays a central role in the etiology of galactosemic cataracts by effecting the conversion of galactose to dulcitol (galactitol) and that an agent capable of inhibiting aldose reductase can prevent the detrimental accumulation of dulcitol in the lens. Furthermore, a relationship between elevated levels of glucose and an undesireable accumulation of sorbitol has been demonstrated in the lens, peripheral nervous cord and kidney of diabetic animals, see A. Pirie and R. van Heyningen, Exp. Eye Res., 3, 124 (1964); L. T. Chylack and J. H. Kinoshita, Invest. Ophthal., 8, 401 (1969) and J. D. Ward and R. W. R. Baker, Diabetol., 6, 531 (1970).
1,3-Dioxo-1H-benz[de]isoquinoline-2(3H)-acetic acid has been reported to be an effective inhibitor of aldose reductase, see D. Dvornik et al, Science, 182, 1146 (1973), and to be used for the treatment of diabetic complications such as diabetic cataracts, neuropathy, nephropathy and retinopathy, see K. Sestanj, N. Simrad-Duquesne and D. Dvornik, U.S. Pat. No. 3,821,383, June 28, 1974. Other compounds having a similar utility are the thioxo-1H-benz[de]isoquinoline-2(3H)-acetic acid derivatives of K. Sestanj, U.S. Pat. No. 4,254,108, Mar. 3, 1981, and 1H-benz[de]isoquinoline-2(3H)-acetic acid derivatives of K. Sestanj, U.S. Pat. No. 4,254,109, Mar. 3, 1981. Still other compounds having a similar utility are 2-thioxobenz[c,d]indole-1(2H)-acetic acid derivatives of K. Sestanj, U.S. Pat. No. 4,369,188, Jan. 18, 1983; N-naphthoylglycine derivatives of K. Sestanj et al, U.S. Pat. No. 4,439,617, Mar. 27, 1984; N-(naphthalenylthioxomethyl)amino acid derivatives of K. Sestanj et al, U.S. Pat. No. 4,391,816, July 5, 1983; N-[(2-naphthalenyl)thioxomethyl]glycine derivatives of K. Sestanj, U.S. Pat. No. 4,447,452, May 8, 1984; and N-[[6-(lower alkoxy)-5-(trifluoromethylthio)-1-naphthalenyl]thioxomethyl]-N-(lower alkyl)-glycines of F. Bellini et al, U.S. Pat. No. 4,391,825, July 5, 1983. Accordingly, these compounds represent an important new approach for the treatment of diabetes mellitus.
The present application discloses the novel N-[[6-methoxy-5-(trifluoromethyl)-1-naphthalenyl]thioxomethyl]-N-methylgly cine S-oxide and the amide thereof represented below by formula I, which are of effective inhibitors of aldose reductase. They are structurally different from the above noted aldose reductase inhibitors. The closest of the previously reported compounds are seen in U.S. Pat. No. 4,439,617 (Example 52) and U.S. Ser. No. 743,336, filed June 10, 1985. The present derivatives differ by being S-oxides.